Warehouse-door.



Patented August 2, 1904.

PATENT OFFICE.

JOHN ERIVOOD, OF CHICAGO, ILLINOIS.

WAREHOUSE-DOOR.

SPECIFICATION forming part of Letters Patent No. 766,761, dated August 2, 1904.

Application filed March 28, 1903.

To all whom, it may concern:

Be it known that I, J OHN Enwooo, a citizen of the United States, residing at No. 1604: 'est Adams street, in the city of Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in "arehouse-Doors, of which the following is a specification, reference being had to the accompanyingdrawings, forminga part thereof.

This invention consists in improvements in the structure and mode of operating doors adapted for warehouses and commonly called warehouse-doors.

It consists in the features of construction set out in the claims.

In the drawings, Figure 1 is a front elevation of a door and the adjoining portions of the wall in which it is hung having features of construct-ion embodying my invention. Fig. 2 a section at the line 2 2 on Fig. 1. Fig. 3 is a similar view showing the door in elevated position. Fig. 4 is a section at the line L 4 on Fig. 1.

My improved door is made in two sections hinged together at a longitudinal horizontal line, the lower section 1 being preferably longer than the upper section 2 by about the thickness of the door, this being merely a matter of convenience and not of necessity. The upper section is hinged to a horizontal bar 3, which is guided on vertical bars *I 4, which are most conveniently formed each as the vertical limb of a frame of which an upper horizontal limb 5 may be bolted to the timbers of the ceiling overhead, while an oblique side 6 constitutes a brace for the lower end of the vertical limb which constitutes the guide-bar. On the upper side of the horizontal bar above each lateral edge of the door there is mounted a pulley 8, and to the ceiling or any overhead support there are mounted in line directly above said pulleys, respectively, pulleys 9 9. Adjacent to the pulley 9 at the left-hand side and conveniently journaled in the same bracket is a guide-pulley 10, and in suitable position with respect to the pulley 9 at the right hand there is mounted a guide-pulley 9 and at a little distance therefrom a double-groove pulley 10. At the opposite lateral edges of each lower Serial No. 149,959. (No model.)

section of the door at the foot there is mounted a tracking pulley or wheel 11, for which a guide-track 12 is provided on the wall parallel with the door-opening, said guide-track having preferably a guard-flange 13 at the outer side to prevent the door from swinging edgewise laterally. To studs 23 23, set in the edges of the lower door-section close to the lower end between the edges of the door, respectively, and the pulleys 11, there are secured the lifting-cables 14 and 2a. The cable 14: at one side passes up along the edge of the door through an aperture 15 in the plate 3, over the pulley 9, down about the pulley 8, and thence up over the pulley 9, and thence over the pulley 10, down to the weight 18. The other cable, 2%, passes up over the pulley 9 at the other side of the door, down about the pulley 8, and thence up over the pulley 10, and thence across above the door to the other side and over the pulley 10 in the second groove thereof and down to the weight 18. The weight 18 is designed to conventionally represent any counterpoise for the doors.

In practice it may be desirable to provide varying counter-poise, which may be done by any well known expedients. (Not shown.) The door may have a handle 19 at the foot for operating it and preferably a handle 20 near the hinge-line between the two sections for buckling the door or starting it in direction away from the wall at the hinge when it should fold away from the wall, as hereinafter explained.

' The operation of my improved door is asfollows: Vhen the operator, seizing the lower handle 19, lifts the door, whose down weight is at this position a little more than counterpoised by the countcrpoise-weight 15, but not enough to overcome the inertia and frictional resistance to starting, the entire door-2 (1., both sections-will ascend bodily without buckling, the pulleys 8 approaching the pulleys 9 to the full extent of the ascending movement of the door until the bar 3 reaches the stops 4 on the vertical guides 4:. No buckling or folding of the door willoccur so long as the upper section can thus move upward, because the draft of the lifting-cables, although they are attached at the lower end of the lower section, operates first upon the pulleys 8 8 at the top, the friction of the pulley system and the stretch of the cable constituting a differentialbetween the draft of the top and bottom, making the draft operate at the top to that extent more quickly than at the bottom and tending to prevent the buckling of the door either toward the wall or away from the same, which would tend to occur if the draft were greater or more quickly experienced at the bottom. When the upward movement of the bar Sis stopped, so that the entire draft of the cables must take effect at the bottom, the door will tend to buckle away from the wall, and the operator must assist it by using the handle 20. It will be noticed that up to this point while the whole weight of both sections has been lifted the cable and pulley system operates to give the weight triple value for counterpoising the door, but that from the point at which the ascent of the pulleys 8 is prevented the weight will operate with onlyits normal value as a counterpoise; but also it will be noticed that from this point the door is not lifted bodily, but is only swung away from the wall by folding at the middle-hinge line, so that,

' with some variation not necessary to take into account, the door may be balanced by a counterpoise of half its weight. The position of the bar 3 when the door is closed is slightly above the upper margin ofthe door-opening, enough only to allow the proper lap of the door on the margin of the opening, and the distance which the bar moves upward to reach the stop 4: is designed to be suflicient to con stitute a safe base for the frame formed by said base and the two sections of the door when folded up in the position shown in Fig. 3, for it will be understood that if the two sections of the door were folded up close together the weight of the door thus outstretched horizontally, operating over so narrow a base as the mere thickness of the two sections, would very severely strain any support and tend to wrench it from the wall. A specific purpose, therefore, of the construction which affords opportunity for lifting the door a short-distance before it begins to fold is to permit the two members of the door to en'- tirely clear the door-opening while still spread apart at their unconnected horizontal edges without making the radius of the arc in which the door must swing and which must be kept clear to permit it to swing in the room materially more than half the height of the door.

Although the means for lifting and upholding the part or parts to which the upper doorsection is hinged includes part of the same cable which also by being connected to the lower door-section at the bottom serves as part of the means for lifting that section at the bottom, it will be evident that this is not a necessity, and by phrase such as means for performing these two parts of the action ically.

A distinct advantage arises from the circumstance that the upper door-section 2 is,

hinged, as shown, at the corner of its upper edge opposite the wall side of the door rather than at the wall-side corner-that is, the corner next the wallin that the tendency of the door hanging freely from the point of suspension at said upper inner corner is to take such a position that the pivot of the hinge between the two sections and the longitudinal horizontal lines containing the centers of gravity of the two sections, respectively, which may be assumed to be at substantially the middle point of their width, will all stand in the same vertical plane with the pivotal line of the hinge of the other section at the top.

This, it will be seen, will cause the door at its folding-line to buckle a little away from the vertical plane of the \vallthat is, to be not. closed together; but when the counterpoise force operating on the lower end to uplift the door is enough to fully counterpoise the down weight of the door when it is forced closed at the middle-line joint between the two sections, so that there is a little net upward stress operating at the ,lower end of the lower section, that stress operating in a plane extending from the longitudinal horizontal lines of attachment of the lifting-cablethat is, the axis of the pulleys 11-through the upperhinge pivotal line, and said plane being inward from the pivotal line of' the hinge connection between the two sections will tend to hold the door closed; but a very slight pull at the handle 20 will unbuckle the door that is, will force the pivotal line of the middle hinges past said plane of stressthus making the door very easy to start. A like pressure toward the vertical plane of the wall will be sufficient to close the door at the joint between the two sections and place it in position where it will be held by the slight excess of upward stress not sufficient to start the door upward.

I claim I 1. A door formed in two sections longitudinally horizontally hinged together, in combination with a support to which the upper section is hinged at the upper edge; vertical guides for said support provided with stops to limit its upward movement, and means for lifting the door connected with said support and with the lower section of the door.

2. A door consisting of two sections hinged together at a longitudinal horizontal line and adapted to fold; an element to which the upper portion is hinged at its upper edge, said element having a limited range of upward I do consider, however, the struc movement; means for guiding and stopping it in such movement, and means for lifting and upholding said element and for operating on the lower door-section at its lower edge to uplift and uphold it.

3. A door consisting of two sections hinged together in a longitudinal horizontal line; an element to which the upper section is hinged at the upper edge; means for lifting and upholding said element, operating also on the door at the lower edge of the lower section to lift the same, and stops to limit the upward movement of said element.

L. A door consisting of two sections longitudinally horizontally hinged together and adapted to fold; a horizontal bar to which the upper door-section is hinged at the upper edge; lifting-cables connected to the lower door-section near the lower edge; pulleys supported in fixed position over which the cables run and pulleys mounted on the bar about which the cables run from the first-mentioned pulleys; stops limiting the upward movement of the bar and guide-pulleys above the level of the stops to which the cables run from the pulleys on the door, and means for operating the cables to lift and sustain the door whereby the door is lifted without folding until the bar reaches the stops and the subsequent operation of the cable lifts the door by folding the same.

5. A door consisting of two sections hinged together at a longitudinal horizontal line and adapted to fold; a horizontal bar to which the upper section is hinged at the upper edge; vertical guides for such bars and stops thereon limiting its upward movement; corresponding pulleys mounted respectively on the bar and at a fixed support above the same and guidepulleys also mounted on such fixed support above the level of the stops; cables attached to the lower door-section near the lower edge, extending thence up along the edges of the door, about the overhead pulleys, and thence down about the pulleys on the bar, and thence up to and about the guide-pulleys, and a counterweight carried by the cables.

6. A door formed in two sections horizontally hinged together; a support to which the upper section is hinged at its upper edge, and means operating on the door at the lower edge of the lower section to lift the same, the pivotal line of the hinge-joint between the two door-sections being at the side toward the wall from the vertical plane of the connection of the lifting means at the lower edge of the lower section, and the longitudinal horizontal line of the hinge of the upper door-section to said support being at the opposite side of said vertical plane.

7. Adoor formed in two sections longitudinally horizontally hinged together, in combination with a support to which the upper section is hinged at its upper edge, and means pivotally connected to the door at the lower edge of the lower section to lift the same, said last-mentioned connection being at a plane intermediate the two surfaces of the door, the pivotal line of the hinge-joint between the two door-sections being substantially at the plane of the surface of the door toward the wall, and the pivotal line of the hinge at the top of the upper door-section being substantially at the opposite surface of the door.

In testimony whereof I have hereunto set my hand, in the presence of two witnesses, at Chicago, Illinois, this 21st day of March, A. D.

JOHN ERWVOOD. In presence of CHAS. S. BURTON, FRED. G. FISCHER. 

